Merge "Linearly complete overscroll stretch when close" into sc-dev (5a1f9df8) · Commits · e / os / android_frameworks_base

core/java/android/widget/EdgeEffect.java

+79 −43

Original line number	Diff line number	Diff line
		@@ -97,12 +97,28 @@ public class EdgeEffect {
		*/
		private static final double VELOCITY_THRESHOLD = 0.01;

		/**
		* The speed at which we should start linearly interpolating to the destination.
		* When using a spring, as it gets closer to the destination, the speed drops off exponentially.
		* Instead of landing very slowly, a better experience is achieved if the final
		* destination is arrived at quicker.
		*/
		private static final float LINEAR_VELOCITY_TAKE_OVER = 200f;

		/**
		* The value threshold before the spring animation is considered close enough to
		* the destination to be settled. This should be around 0.01 pixel.
		*/
		private static final double VALUE_THRESHOLD = 0.001;

		/**
		* The maximum distance at which we should start linearly interpolating to the destination.
		* When using a spring, as it gets closer to the destination, the speed drops off exponentially.
		* Instead of landing very slowly, a better experience is achieved if the final
		* destination is arrived at quicker.
		*/
		private static final double LINEAR_DISTANCE_TAKE_OVER = 8.0;

		/**
		* The natural frequency of the stretch spring.
		*/
		@@ -587,6 +603,7 @@ public class EdgeEffect {
		if (mState == STATE_RECEDE) {
		updateSpring();
		}
		if (mDistance != 0f) {
		RecordingCanvas recordingCanvas = (RecordingCanvas) canvas;
		if (mTmpMatrix == null) {
		mTmpMatrix = new Matrix();
		@@ -637,6 +654,7 @@ public class EdgeEffect {
		mHeight // max vertical stretch in pixels
		);
		}
		}
		} else {
		// Animations have been disabled or this is TYPE_STRETCH and drawing into a Canvas
		// that isn't a Recording Canvas, so no effect can be shown. Just end the effect.
		@@ -730,6 +748,26 @@ public class EdgeEffect {
		if (deltaT < 0.001f) {
		return; // Must have at least 1 ms difference
		}
		mStartTime = time;

		if (Math.abs(mVelocity) <= LINEAR_VELOCITY_TAKE_OVER
		&& Math.abs(mDistance * mHeight) < LINEAR_DISTANCE_TAKE_OVER
		&& Math.signum(mVelocity) == -Math.signum(mDistance)
		) {
		// This is close. The spring will slowly reach the destination. Instead, we
		// will interpolate linearly so that it arrives at its destination quicker.
		mVelocity = Math.signum(mVelocity) * LINEAR_VELOCITY_TAKE_OVER;

		float targetDistance = mDistance + (mVelocity * deltaT / mHeight);
		if (Math.signum(targetDistance) != Math.signum(mDistance)) {
		// We have arrived
		mDistance = 0;
		mVelocity = 0;
		} else {
		mDistance = targetDistance;
		}
		return;
		}
		final double mDampedFreq = NATURAL_FREQUENCY * Math.sqrt(1 - DAMPING_RATIO * DAMPING_RATIO);

		// We're always underdamped, so we can use only those equations:
		@@ -745,9 +783,7 @@ public class EdgeEffect {
		+ mDampedFreq * sinCoeff * Math.cos(mDampedFreq * deltaT));
		mDistance = (float) distance / mHeight;
		mVelocity = (float) velocity;
		mStartTime = time;
		if (isAtEquilibrium()) {
		mState = STATE_IDLE;
		mDistance = 0;
		mVelocity = 0;
		}

libs/hwui/effects/StretchEffect.h

+13 −3

Original line number	Diff line number	Diff line
		@@ -40,9 +40,7 @@ public:

		StretchEffect() {}

		bool isEmpty() const {
		return MathUtils::isZero(mStretchDirection.x()) && MathUtils::isZero(mStretchDirection.y());
		}
		bool isEmpty() const { return isZero(mStretchDirection.x()) && isZero(mStretchDirection.y()); }

		void setEmpty() {
		*this = StretchEffect{};
		@@ -118,6 +116,18 @@ public:
		}

		private:
		// The epsilon for StretchEffect is less than in MathUtils because
		// the range is 0-1 for an entire screen and should be significantly
		// less than 1 pixel for a smooth stretch animation.
		inline static bool isZero(float value) {
		// Using fabsf is more performant as ARM computes
		// fabsf in a single instruction.
		return fabsf(value) <= NON_ZERO_EPSILON;
		}
		// This should be good for 1/25,000 of a screen and should be good for
		// screens with less than ~8000 pixels in one dimension with only 1/4 pixel
		// cut-off.
		static constexpr float NON_ZERO_EPSILON = 0.00004f;
		static sk_sp<SkRuntimeEffect> getStretchEffect();
		mutable SkVector mStretchDirection{0, 0};
		mutable std::unique_ptr<SkRuntimeShaderBuilder> mBuilder;